ASP.NET Page Life Cycle Events tutorials

Within each stage of the life cycle of a page, the page raises events that
you can handle to run your own code.

For control events, you bind the event handler to the event, either
declaratively using attributes such as onclick, or in code.

The following table lists the page life-cycle events that you will use most
frequently.

PageEvent

Description

PreInit

This event raised after the start stage is complete and before the
initialization stage begins.

Init

Raised after all controls have been initialized and any skin settings
have been applied. The Init event of individual controls occurs
before the Init event of the page.Use this event to read or initialize
control properties.

InitComplete

Raised at the end of the page's initialization stage. Only one operation
takes place between the Init and InitComplete events: tracking
of view state changes is turned on. View state tracking enables controls to
persist any values that are programmatically added to the ViewState
collection.

Until view state tracking is turned on, any values added to view state
are lost across postbacks. Controls typically turn on view state tracking
immediately after they raise their Init event. Use this event to
make changes to view state that you want to make sure are persisted after the
next postback.

PreLoad

Raised after the page loads view state for itself and all controls, and
after it processes postback data that is included with the Request
instance.

Load

The Page object calls the OnLoad method on the
Page object, and then recursively does the same for each child control
until the page and all controls are loaded. The Load event of
individual controls occurs after the Load event of the page. Use
the OnLoad event method to set properties in controls and to
establish database connections.

Control events

Use these events to handle specific control events, such as
a Button control's Click event or
a TextBox control's TextChanged event.

LoadComplete

Raised at the end of the event-handling stage.

Use this event for tasks that require that all other controls on the page
be loaded.

PreRender

Raised after the Page object has created all controls that are
required in order to render the page, including child controls of composite
controls. (To do this, the Page object calls
EnsureChildControls for each control and for the page.)

The Page object raises the PreRender event on
the Page object, and then recursively does the same for each child
control. The PreRender event of individual controls occurs after
the PreRender event of the page.

Use the event to make final changes to the contents of the page or its
controls before the rendering stage begins.

PreRenderComplete

Raised after each data bound control whose DataSourceID property is
set calls its DataBind method.

SaveStateComplete

Raised after view state and control state have been saved for the page
and for all controls. Any changes to the page or controls at this point
affect rendering, but the changes will not be retrieved on the next postback.

Render

This is not an event; instead, at this stage of processing,
the Page object calls this method on each control. All ASP.NET Web
server controls have a Render method that writes out the control's
markup to send to the browser.

If you create a custom control, you typically override this method to
output the control's markup. However, if your custom control incorporates
only standard ASP.NET Web server controls and no custom markup, you do not
need to override the Render method.

Unload

Raised for each control and then for the page.

In controls, use this event to do final cleanup for specific controls,
such as closing control-specific database connections.

For the page itself, use this event to do final cleanup work, such as
closing open files and database connections, or finishing up logging or other
request-specific tasks.

Thank you for visiting www.cbtSAM.com. This site is dream of Samir Patel, when most people dream when in sleep, my dream doesn't let me sleep. cbtSAM Web site is provided as a service and learning tool to the public. While the information contained within the site is periodically updated,no guarantee is given that the iormation provided in this Web site is correct, complete, and up-to-date. We are not responsible for... Read More .